SERCOS-III combines real-time and Ethernet

Interests Group SERCOS (IGS) interface e.V. recently started a project to link its existing SERCOS interface and Ethernet to form SERCOS-III. The organization reported on its efforts at the recent SPS/IPC/ Drives 2003 show. SERCOS-III is based on the established, real-time mechanisms of the SERCOS interface, which continues to work on the principle of cyclic data tran...

By Staff January 1, 2004

Interests Group SERCOS (IGS) interface e.V. recently started a project to link its existing SERCOS interface and Ethernet to form SERCOS-III. The organization reported on its efforts at the recent SPS/IPC/ Drives 2003 show.

SERCOS-III is based on the established, real-time mechanisms of the SERCOS interface, which continues to work on the principle of cyclic data transfer with an exact time pattern. SERCOS says hardware-based synchronization is the indispensable prerequisite for reliably realizing motion applications, such as electronic line shafts in printing machines, packaging machines, or multi-axes machine tools.

SERCOS-III has been defined so any standard IP telegram, such as TCP/IP, can be transmitted in a non-real-time time slot, moving in parallel to the real-time data transfer required for motion control. The SERCOS-III controller can exchange these telegrams with super-ordinate devices in the network. As a result, SERCOS-III combines the established real-time mechanisms and its diagnostic capabilities with the universal communications available via Ethernet.

Consequently, SERCOS-III is not only an open interface, but is also an all-purpose automation interface, similar to today’s increasingly common, direct integration of I/O devices, electric-hydraulic axes, frequency converters, and servo drives. SERCOS-III is being defined so that real-time communication will be compatible with the established SERCOS mechanisms, which means that upgrading existing software solutions will be possible at low cost and minimal required effort.

Another important goal of the SERCOS-III project is reducing interface costs per node by offering low-priced, powerful hardware components. Various hardware options are being examined, such as an FPGA-based controller and a multi-protocol communication controller. These considerations will be finalized in the next several months. Likewise, the rough technical concept of SERCOS-III has been worked out and verified, and IGS reports that the first SERCOS-III prototypes will be available in 2005.